1. Field of the Invention
The present invention relates to a brake device for a motorcycle including a brake pedal, a master cylinder, and an operational amount detector for detecting the rotational amount of the brake pedal.
2. Description of Background Art
A technique is known wherein a potentiometer is used to obtain the operational amount of a brake pedal to provide control information for an ABS (Antilock Brake System). See, for example, FIGS. 1 and 2 of Japanese Patent Laid-Open No. Hei 9-164925.
As shown in FIG. 1 of Japanese Patent Laid-Open No. Hei 9-164925, a potentiometer (60) (the numbers in parentheses are the same as the numbers shown in Japanese Patent Laid-Open No. Hei 9-164925) and a brake pedal (40) are mounted on a bracket (30). An arm (70) extends from the brake pedal (40) to the potentiometer (60). The arm (70) is rotatable with the brake pedal (40).
As shown in FIG. 2 of Japanese Patent Laid-Open No. Hei 9-164925, a pin (71) is mounted at the front end of the arm (70). The pin (71) is engaged with a bifurcated arm (63a) extending from the potentiometer (60), so that the operational amount of the brake pedal (40) can be detected by the potentiometer (60).
In the case of applying the arrangement of the potentiometer (60) shown in Japanese Patent Laid-Open No. Hei 9-164925 to a motorcycle, the operational direction (rotational direction) of the brake pedal is changed from a longitudinal direction to a vertical direction, so that the layout of parts in the periphery of the brake pedal is susceptible to limitation.
Further, if the potentiometer (60), the brake pedal (40), and an input rod (21) are provided in a motorcycle without any changes, the potentiometer (60) and the input rod (21) are located directly below the brake pedal (40), so that it is difficult to ensure a road clearance.